It is well known in the art that there are solid drugs which are highly insoluble in water. Due to their low solubilities in water, these drugs have a correspondingly low degree of bioavailability. One such drug, in particular, is ibuprofen. Ibuprofen is a non-steroidal anti-inflammatory drug which is commonly used to relieve pain and to treat inflammatory conditions. Ibuprofen is a white powder or crystal which is practically insoluble in water. Ibuprofen is absorbed from the gastro-intestinal tract and the peak plasma concentrations occur approximately one to two hours after ingestion of the solid powder or crystal form.
A standard dosage form widely in use for the delivery of ibuprofen is the solid dosage form or tablet. The absorption time of a solid dosage form (tablet) is relatively long because of two significant factors. The first factor is that the drug; being introduced as a solid, needs to first dissolve before it can be absorbed by the body. The second factor is that absorption into the body is further delayed because ibuprofen is practically insoluble in water or the acidic environment of the stomach.
Several processes have been developed in efforts to increase the solubility and, hence, the bioavailability of ibuprofen. One such prior art process disclosed in U.S. Pat. No. 5,071,643 to Yu et al., discloses the use of a water-based solvent system for enhancing the solubility of an acidic, basic, or amphoteric pharmaceutical agent, such as ibuprofen, to produce a highly concentrated solution suitable for encapsulation. The solvent system includes polyethylene glycol containing 0.2-1.0 mole equivalents of an ionizing agent per mole equivalent of pharmaceutical agent and 1-20% water. This water-based solvent system provides for a highly concentrated solution capable of encapsulation into a small enough vessel, such as a soft gel capsule, to permit easy swallowing and to provide a pharmaceutically effective dose of a pharmaceutical agent such as ibuprofen.
The method disclosed in the Yu et al. reference solubilizes the pharmaceutical agent (ibuprofen) in a water-based solvent system utilizing a solubility enhancing agent to solubilize the ibuprofen.
It would be advantageous and desirable to have an oil-based ibuprofen solution which is capable of supporting ibuprofen concentrations sufficient for encapsulation in a liquid dosage form.
By combining the oil-based ibuprofen solution with a dosage form such as a filled soft gelatin capsule, optimal advantage can be taken of the potential potency and efficacy of the poorly water-soluble ibuprofen. Also, because the formulation is a true solution, content uniformity of dosage is assured. The present invention provides an improved ibuprofen solution and ibuprofen dosage form for providing the relatively water insoluble ibuprofen with a mechanism for greater dissolution and, hence, greater bioavailability than a solid dosage form which includes all of the aforementioned advantages.